Build transitive lint reports for apex modules

Build and export transitive lint report zips for apex modules.

Bug: 153485543
Test: m TARGET_BUILD_APPS=com.google.android.wifi lint-check dist
Change-Id: I5a1805440452301a7e2c4ca91482b989638b54fb
diff --git a/apex/androidmk.go b/apex/androidmk.go
index 10cc4b6..e739e2b 100644
--- a/apex/androidmk.go
+++ b/apex/androidmk.go
@@ -353,6 +353,10 @@
 				if apexType == imageApex {
 					fmt.Fprintln(w, "ALL_MODULES.$(my_register_name).BUNDLE :=", a.bundleModuleFile.String())
 				}
+				if len(a.lintReports) > 0 {
+					fmt.Fprintln(w, "ALL_MODULES.$(my_register_name).LINT_REPORTS :=",
+						strings.Join(a.lintReports.Strings(), " "))
+				}
 
 				if a.installedFilesFile != nil {
 					goal := "checkbuild"